Prime 4 and Engine OS Tempo change greyed out....sometimes?

Hello, was wondering that the deal is with the Tempo being greyed out. I have the prime 4 and when I hit grid edit the option to double or half is greyed out sometimes. I had a track that was reading at 85bpm but was supp to be 175 and the track was playing double speed. Was supp to just hit edit grid and double the tempo but it was greyed out. Not sure what I did but then it wasn’t and I changed it only to have it go back to half time. I went back to the software and it was greyed out as well, then messed around with loading and unloading tracks and then it came up again. I changed it and synced it back up to the USB to only find it didn’t change the tempo! I Ended up erasing the set on the USB and re-syncing and it eventually took it the new tempo. Is there circumstances that would make it greyed out, certain conditions I need to watch for?

Thanks

Could be a grid locked track or a grid with manually set anchors. However, these would not be set automatically.

On this specific track I did add a bunch of Anchors because the grid was shifting. I guess that is why it was greyed out. What is the purpose of the Anchors I dont understand. I went along the whole track and kept adding an anchor everytime it moved, but the grid still drifts off after doing that. I saw a video talking about the reason for the drift is that the tempo is wrong. I thought adding anchors would fix it but the video shows someone guessing the right tempo and adding it manually? What is the real way to fix a track that has a drifting grid?

I usually just leave tracks like that to drift, unless you specifically need every beat anchored I don’t think it’s worth the bother. Usually lining up the first 8 or so beats is enough to set a loop in for mixing.

I take it these aren’t dance music tracks and they are live instruments? It’s an unfortunate side effect of life drums that they will be out of time.